The luminescence quenching and strengthen effects of porous silicon(PS) caused by adsorbing organic molecular were investigated.The results indicate that luminescence in PS may actually be luminescence from molecules attached to the Si surface.By using n butylamine as carbon resource,carbon film is deposited on the PS surface by means of radio frequency glow discharge plasma system.Changing passivated temperature and passivated time,PL of the passivated samples shows an obvious change,and the highest light emitting efficiency and the wavelength required could be acquired by adjusting passivated temperature and passivated time.These results show that carbon films might be an excellent passivation films on porous silicon and show a brilliant application prospect.